//
// Created by jiaopan on 8/19/20.
//

#include <string>
#include <vector>
#include <opencv2/opencv.hpp>

using namespace cv;
class Utils{
public:
    static unsigned char* matToBytes(Mat& image, unsigned char* &bytes) {
        int size = image.total() * image.elemSize();
        bytes = new unsigned char[size];  //  have to delete[] that later
        std::memcpy(bytes, image.data, size * sizeof(unsigned char));
        return bytes;
    }

    static Mat bytesToMat(unsigned char* bytes, int width, int height) {
        Mat image = Mat(height, width, CV_8UC3, bytes).clone(); // make a copy
        return image;
    }

    static std::string base64Decode(const char* Data, int DataByte){
        const char DecodeTable[] ={
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                62, // '+'
                0, 0, 0,
                63, // '/'
                52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
                0, 0, 0, 0, 0, 0, 0,
                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
                13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
                0, 0, 0, 0, 0, 0,
                26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
                39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
        };
        std::string strDecode;
        int nValue;
        int i = 0;
        while (i < DataByte){
            if (*Data != '\r' && *Data != '\n'){
                nValue = DecodeTable[*Data++] << 18;
                nValue += DecodeTable[*Data++] << 12;strDecode += (nValue & 0x00FF0000) >> 16;
                if (*Data != '='){
                    nValue += DecodeTable[*Data++] << 6;strDecode += (nValue & 0x0000FF00) >> 8;
                    if (*Data != '='){
                        nValue += DecodeTable[*Data++];
                        strDecode += nValue & 0x000000FF;
                    }
                }
                i += 4;
            }
            else{
                Data++;
                i++;
            }
        }
        return strDecode;
    }

    static cv::Mat base64ToMat(std::string &base64_data){
        cv::Mat img;
        std::string s_mat;
        s_mat = base64Decode(base64_data.data(), base64_data.size());
        std::vector<char> base64_img(s_mat.begin(), s_mat.end());
        img = cv::imdecode(base64_img, CV_LOAD_IMAGE_COLOR);
        return img;
    }

    ~Utils() {

    }
};